1. Technical Field
The present invention relates to: a method of controlling a functional liquid supply apparatus which pressurizes a plurality of functional liquid tanks to thereby supply under pressure each kind of functional liquid from each of the functional liquid tanks to a functional liquid droplet ejection head which ejects functional liquid droplets; a functional liquid supply apparatus; a liquid droplet ejection apparatus; a method of manufacturing an electro-optical device; an electro-optical device; and an electronic device.
2. Related Art
Among ink jet printers which are known as a kind of liquid droplet ejection apparatus, there is one in which ink cartridges (functional liquid tanks) are located blow a print head (functional liquid droplet ejection head). The ink cartridges are pressurized by an ink pressurizing means to thereby supply under pressure the ink (functional liquid) stored in the ink cartridges to the print head. JP-A-2002-166569 is an example of related art.
The functional liquid droplets to be ejected from the functional liquid droplet ejection head are extremely minute (ultra-fine). Therefore, the pressure of the functional liquid in passages inside the head (hereinafter also referred to as “in-head pressure”) of the functional liquid droplet ejection head gives an influence on the functional liquid droplets to be ejected from the functional liquid droplet ejection head. Therefore, in order to perform imaging (drawing) at a high accuracy by using the functional liquid droplet ejection head, it is necessary to control the pressurizing force by the pressurizing means so that the in-head pressure becomes a predetermined set pressure.
However, in case the liquid droplet ejection apparatus has a plurality of functional liquid tanks for storing therein plural kinds of functional liquids which are different from one another, there is the following problem. Namely, if these functional liquid tanks are pressurized at a uniform pressure, there will be a difference in pressure loss due to the difference in the viscosity, or the like, of each of the functional liquids, even if the lengths and diameters of tubes to the in-head passages are made the same. As a result, the in-head pressure cannot be made to the predetermined set pressure and may give an adverse effect on the imaging operation.